Combustors are known in the art for igniting fuel with air to produce combustion gases having a high temperature and pressure. For example, gas turbine systems, aircraft engines, and numerous other combustion-based systems may include one or more combustors that mix a working fluid, such as air, with fuel and ignite the mixture to produce high temperature and pressure combustion gases. The combustion gases may then be used to rotate a turbine, provide thrust, or perform various other forms of work.
Each combustor may include an end cover that provides an interface for supplying multiple fuels, diluents, and/or additives to fuel nozzles inside the combustor. The end cover may include multiple internal fluid passages, and an insert may be installed between the end cover and each fuel nozzle to connect the different fluid passages inside the end cover to corresponding fluid passages inside the fuel nozzles. In this manner, a single end cover design may be adapted to fit multiple fuel nozzle designs.
Various seals, such as the seals disclosed in U.S. Pat. No. 7,134,287 and assigned to the same assignee as the present invention, may be installed between the end cover and the insert to prevent leakage between the various fluid passages inside the end cover and the insert. During manufacture and assembly, screws, bolts, joints, or other fasteners may be used to hold the insert and seals in place with respect to the end cover so that the assembly may be leak tested, shipped, and otherwise held together. The specific type, size, and location of the fasteners involves several competing design considerations. For example, multiple smaller fasteners may be used around the circumference of the insert to ensure a relatively consistent force is applied to each seal. However, the use of multiple fasteners to attach the insert to the end cover necessarily increases the number of parts, machining, and time associated with assembling and testing the end cover. In addition, the available surface area of the end cover limits the number and size of the fasteners between the insert and the end cover. Therefore, an improved system and method for assembling an end cover of a combustor that reduces the number of parts, machining, assembly time, and/or required surface area on the end cover would be useful.